Furnace stoker



Sept. 5, 1933. B. COLEMAN ll-:r Al.

FURNACE STOKER Filed sept. 2. 1930 2 Sheets-Sheet 1 E Il A IIJUAT1-camas i Sept. 5, 1933. B. coLEM'AN Er AL 1,925,790

FURNACE sToKER Filed Sept. 2, 1930 2 Sheets-Sheet 2 inw-:mons

ATTORN EYg Patented Sept. 5, 1933 UNITED STATES PATENT OFFICE FURNACESTOKER Bert Coleman and Silas J. Hendershott, Detroit, Mich., assignorto Ever-Ready Coal Burner Company, Michigan Detroit, Mich., a.corporation of The invention relates to automatic stokers for domesticheating furnaces and more particularly' to a construction providing forthe shaking of the furnace grates either automatically or manually.

The object of the invention is to provide an improved construction forthe operation of the grates constructed in a simple manner and arrangedfor convenient access for the manual operation of the grate. A furtherobject is to provide an automatic mechanism for operating the gratesduring the automatic operation of the furnace so as to obtain anenicient operation of the furnace.

These and other objects are attained inthe construction hereinafterdescribed and illustrated in the accompanying drawings, wherein Figure 1is a. side elevation with parts shown in section of a furnace stokerembodying our in vention; Figure 2 is an end view 'of the stoker; Figure3 is a transverse sectional view on th line 3 3 of Figure 1;

Figure 4 is a top plan view of a portion of the mechanism;

Figure 5 is a perspective view of the stoker mechanism; f Y

Figure 6 is an enlarged sectional View of a portion of the structureshown in Figure 1.

Figure 7 is a sectional detail View of a portion of the retort andgrate. i, In the construction as illustrated in the drawings, 1represents a body portion or baseabove which is mounted the fuel hopper2. The body 1 is hollow and is provided at the bottom thereof with atransversely extending screw conveyor 3 which projects outwardly fromthe body and is enclosed by a laterally projecting tube 4. For drivingthe conveyor 3 there is an electric motor 8 connected to the conveyorthrough a suitable 4 gear reduction mechanism 9 in the gear casing 10.The tube 4 communicates with a retort 5 consisting of an inner fuelreservoir 5a and an outer air chamber 5b. A top casting 6 connect-`shaker arm 72 which in turn is mounted on a ing the inner and outerwalls of the retort is per- The stoker as described above is adapted forintermittent feeding of 'coal pr other fuel from the hopper 2 into thefurnace and the intermittent motion` of the screw conveyor 3 is providedby the starting and stopping of the electric mo- C9 tor'8. The controlof the motor 8 is preferably effected by means of `a thermostaticmechanism which may be of any suitable type such as are commerciallymanufactured at the present time. For the preferred construction of thecontrol C5 mechanism reference should be made -to our copendingapplication, Serial No. 479,297, filed on even date herewith.

The motor shaft extends through the gear casing 10 and on the oppositeside of said cas.- ing connects with a suitable blower 61. This blowerhas an air tube 62 extending therefrom which is preferably arrangedadjacent to the fuel tube 4. AtI the delivery end of the air tube therel is an upwardly extending elbow 63 for dis- H charging the air throughthe grates. There is also arranged at the elbow a clean-out door 64 forfacilitatng the removal of foreign matter from the air tube. l F

The driven shaft 65 projects through both ends of the gear casing 10,one end extending into the hopper base and connecting-with the screwconveyor 3. The other end of the shaft 65 is provided with a disk 66 towhich is ecceni trically attached a link 67 for oscillating an arm J 68on a rocker shaft 69. This shaft 69 projects through the hopper base tothe opposite side of said base and is provided with a second arm 70.4 71is a link connecting the arm 70 with the shaft 73 extending parallel tothe fuel feed tube 4. The shaft 73 .projects throughthe ash pit 74 ofthefurnace and is rotatably mounted in a suitable bearing 75 in a lug 76projecting from said elbow 5. 77 is an arm attached to the shaft 73 andextending upwardly beneath the oscillating grate 7. This arm isconnected to a pin 79 on the underside of the grate by means of a link7s.

The shaker arm 72 has at its outer end an arcuate portion 80 providedwith smooth side bearing surfaces 8l and a centrallyarranged notch 82.Adjacent the shaker arm and pivotally secured to the shaft 73 is asocket member 83, having at its upper end a laterally projecting tooth84 adapted' to ride on the bearing surfaces 81 or enter the notch 82when in alignment therewith. Thesocket member has a bifurcated lower endembracing the shaft 73 and pivotally attached thereto by means -of a pin85, thus permitting the ly holds the tooth 84 in the cooperating recess82. 88 is a removable handle member insertable within a socket 89 in thesocket member and having the handle grip 90 at the upperend forfacilitating manual operation of the shaker mechanism.

InJ the operation of the Stoker the main driving motor 8 drives theblower 61 and induces a forced draft through the air tube 62 and intothefuel on the grates. The motor also drives the screw conveyor 3 at areduced speed because of the gear reduction in the gear box 10. Theconveyortakes the solid fuel from the hopper and feeds it through thefuel tube '4 into the center of the retort 5.

The driven shaft 65 through the link 67 oscillates the shaft 69 andconsequently .oscillates the shaker arm 72 about the shaft '73. Thedegree of oscillation of the shaker may be regulated to av certainextent by inserting the connecting link 71 in one of the apertures 91and 92 respectively, thereby obtaining a correspondingly greater orlesser amplitude of movement of the shaker arm.

In the usual position of the socket member 83 it is held in drivingrelation .with the shaker member by the spring 86 which maintains thetooth 84 within the recess 82. In this position ,the shaft 73 is causedto oscillat'e with the shaker member 72 and this in turn oscillates thearm 77 and lthe oscillating grate 7. The arrangement is such thatwhenever the stoker motor 8 is in operation the grate 7 is given aslowoscillatory movement, thereby freeing the` grate from. the ash andpermitting ready access of the air through the grate.

When it is desired to ,manually operate the grates the handle member 88is moved laterally about the pivot pin 85, disengaging the tooth 811from the shaker arm and permitting the shaft 73 and the linkage to thegrate 'l to be operated independently of the stoker motor 8. After themanual operation is complete and the handle member is released the tooth84 is moved 'into contact with the shaker member '72 by the spring 86 sothat in the subsequent automatic oscillation of the shaker member thetooth 84 will always re-enter the recess 82 and couple the grate to.

the automatic shaking mechanism.

As heretofore stated, the stoker motor 8 is controlled by suitablethermostatic mechanism, the arrangement being such'that the motor isintermittently operated and the duration of its operation depends upo'nthe temperature conditions in the room heated by the furnace. It will beseen therefore that the intermittent operation of the motor 8 not onlyintermittently feeds the coal to the fire pot but also intermittentlyfeeds the air to the grate from the blower and intermittently agitatesthegrate for the removal of the ash. The mechanism as describedfunctions as a natural draft burner, the air for combustion being drawnthrough the grates into the fire pot in the same manner as aconventional furnace not provided with any stoker mechanism. Ity

has been found, however, that the addition of the small blower 61 aidsin vassuring complete that the stoker mechanism in the preferred form asoutlined above is not a forced draft machine in the same degree as areother Stoker mechanisms heretofore constructed.

What we claim as our invention: f'

1. In a domestic stoker, an oscillating grate, an oscillating shaft, arocker member secured to said shaft, a link operatively connecting saidgrate and rocker member, an arm journaled on said shaft, means forautomatically oscillating said arm in a plane transverse to said shaft,a member adapted to receive a handle andvpivoted to said shaft forrocking movement toward and away from the plane of vsaid arm, a tooth onsaid member eX- tending toward said arm and drivingly engageabletherewith when said arm is rocked toward said plane and releasable whensaid arm is rocked away from said plane, a spring normally urging saidmember toward the plane of said arm and a handle engaging said memberfor rocking the same away from said plane to release said tooth fromsaid arm whereby said shaft may be oscillated independently. of saidarm.

2. In a domestic Stoker, an oscillating grate, an oscillating shaft, arocker member secured to said shaft, a flink operatively connecting saidgrate and rocker member, an arm journaled on said shaft, said arm havinga laterally extending flange forming a bearing face and provided with anotch therein, means for automatically oscillating said arm in a plantransverse to said shaft, a member adapted to receive a handle andpivoted to saidshaft for rocking movement toward and away from the planeof said arm, a tooth on said member engageable with said notch in saidarm when said member is rocked toward said plane and releasable whensaid member is rocked away from said plane, a spring normally urgingsaid mem-r said notch whereby said shaft may be oscillated independentlyof said arm.

3. In a domestic stoker, an oscillating grate, an oscillating shaft, arocker member secured to said shaft, a link operatively connecting saidgrate and rocker member, an arm journaled on said shaft, a fuelA hopper,a rod extending through said fuel hopper, a driving motor, la connectionfor oscillating said rod from said driving motor, a connection foroscillating said arm from said rod, a member adapted to receive a handleand pivoted to said shaft for rocking movement toward and away from theplane of said arm; a tooth on said member engageable with said arm when'said member is rocked toward said plane and releasable when said memberis rocked away from said plane, a spring normally urging said membertoward the plane of said arm and a handle engaging said member forrocking the same away from said plane to release said tooth from saidarm whereby said shaft.may be oscillated independently of said arm.:

BERT COLEMAN. SILAS J. ERSHOTT.

